Abstract

Chikungunya virus is an emerging threat to the United States because humans are amplifying hosts and competent mosquito vectors are present in many regions of the country. We identified laboratory-confirmed chikungunya virus infections with diagnostic testing performed in the United States from 2010 through 2013. We described the epidemiology of these cases and determined which were reported to ArboNET. From 2010 through 2013, 115 laboratory-confirmed chikungunya virus infections were identified. Among 55 cases with known travel history, 53 (96%) reported travel to Asia and 2 (4%) to Africa. No locally-acquired infections were identified. Six patients had detectable viremia after returning to the United States. Only 21% of identified cases were reported to ArboNET, with a median of 72 days between illness onset and reporting. Given the risk of introduction into the United States, healthcare providers and public health officials should be educated about the recognition, diagnosis, and timely reporting of chikungunya virus disease cases.

Month of illness onset* of chikungunya cases identified in the United States, 2010–2013. * If date of illness onset was missing, the collection date for the earliest specimen was used as a surrogate for month of illness onset.

Number of chikungunya cases identified (2010–2013)* and presence of chikungunya virus vectors (Aedes aegypti and Aedes albopictus) reported to ArboNET (2000–2013) by state. * One hundred seven (93%) of the 115 identified cases had known state of residence.